Thermal refrigeration apparatus



Oct. 29, 1968 R, C, TURNBLADE ET AL 3,407,622

THERMAL REFRIGERATION APPARATUS Pressa/v3 Oct. 29, 1968 R. c. TURNBLADEET AL 3,407,622

THERMAL REFRIGERAT ION APPARATUS Original Filed Feb. 24, 1965 2SheebS-Sheet 2 il? I@ 73% 65 1? @22. f /-Jff fp! Pressa/x9 United StatesPatent Oliice 3,407,622 Patented Oct. 29, 1968 4 claims. (ci. 62-190)ABSTRACT F THE DISCLSURE The invented refrigeration apparatus employs atwo component fluid mixture wherein one iluid component serves as apumping uid while a second fluid component provides the refrigerantaction. A pump condenser and a refrigerant condenser are both coupled toreceive a fluid from a thermal compressor including a free piston.

This is a division of application Ser. No. 434,954 led Feb. 24, 1965.

This invention relates to a refrigeration apparatus and moreparticularly to an improved refrigeration apparatus which includes athermally actuated fluid moving apparatus.

For many applications the need has arisen for a refrigeration apparatuswhich is more compact and with less power requirements than the systemspresently known to the art. Additionally, special applications ofrefrigeration systems to unusual environmental conditions ofzerogravity, acceleration, vibration, and orientation such asencountered in aerospace utilization have given rise to refrigerationand air conditioning problems not easily and eliiciently solved bysystems and apparatus known to the prior art. Under such conditionsconventional apparatus, such as typical piston or reciprocating pumps,for moving the fluid through a refrigerating system are not suitable dueto the weight, electrical power requirements and number of moving partswhich are subject to wear. The necessity for extreme reliability andlong life in such uses is apparent. In order to avoid the electricalpower requirements attempts to employ pumping and compressing apparatuswhich utilizes available thermal energy has been attempted. Thermalpumps and compressors known to the prior art have not, in general, beensatisfactory due to their complexity and relatively low eliiciency.

Accordingly, it is an object of the present invention to provide animproved refrigeration apparatus which can be operated by thermal energyas the prime energy source.

It is another object of the present invention to provide an improvedrefrigerating apparatus which is extremely reliable and has a longoperating life.

It is another object of the present invention to provide a refrigeratingapparatus which is of minimal size and weight.

Another object of the present invention is to provide a refrigeratingapparatus which can be operated by waste heat which is the product ofequipment in connection with which the refrigerating apparatus is used.

It is another object of the present invention to provide a thermallyactuated refrigerating apparatus having modest heat power requirements.

A primary object of the present invention is to provide a refrigeratingapparatus in which pumping fluid and refrigerating lluid can beintermixed ora single fluid used for both functions.

In general, the present invention comprises a refrigerating apparatus inwhich the heat extracted from a heat source is used to vaporize apumping fluid contained within a closed chamber. The heat available issuflicient to boil or vaporize the Vfluid within the chamber to increasethe internal pressure within the chamber. When the internal pressurereaches a predetermined level an outlet valve opens and vaporization ofthe liquid within the chamber continues under a constant pressureprocess. The high pressure fluid can be utilized to drive a refrigerantfluid compressor in a single fluid embodiment in which compressor thetluid is transposed to the required pressure and temperature to completethe condensation expansion steps in a normal refrigeration cycle. In thetwo fluid embodiment compatible pumping fluid and refrigerant liuidsIare intermixed such that the admixed iluids provide thecompression-condensation and expansion steps in the refrigeration cycle.After a predetermined volume of liquid has been vaporized within thechamber the outlet valve closes and a depressurizing means is actuatedto reduce the pressure within the chamber and allow a fresh supply ofliquid to enter the chamber. The liquid inlet valve closes `after theliquid has reached a predetermined level in the chamber and the cycle ofthe pumping apparatus then recommences.

The novel features which are believed to be characteristic of theinvention, both as to its organization and method of operation, togetherwith further objects and advantages thereof will be better understoodfrom the following description considered in connection with theaccompanying drawing in which a presently preferred embodiment of theinvention is illustrated by way of example. It is to be eX- presslyunderstood, however, that the drawing is for the purpose of illustrationand description only, and is not intended as a denition of the limits ofthe invention.

In the drawing:

FIGURE 1 is a partially schematic View in section of a thermalcompressor utilized in the apparatus of the present invention at aii-rst stage of operation;

FIGURE 2 is a view corresponding to FIGURE 1 of the thermal compressorat a subsequent stage of operation;

FIGURE 3 is a view corresponding to FIGURES 1 and 2 of the thermalcompressor at a subsequent stage of operation; i

FIGURE 4 is a View in section of a thermal compressor utilized in thepresent invention in the bypass mode;

FIGURE 5 is a schematic view of an illustrative ernbodiment of atwo-fluid refrigeration apparatus in accordance with the presentinvention; and

FIGURES 6a and 6b are pressure-enthalpy diagrams of the operation of theapparatus of FIGURE 5.

The refrigerating apparatus of the present invention utilizes a fluidpump as shown in FIGURES l, 2 and 3 as more fully described in PatentNo. 3,285,001. The thermal pump of the present invention can be used topump liquid in what is termed hereinafter the pump mode or to pumpcompressed gas or vapor in what is termed hereinafter the `compressormode. In the embodiments of FIGURES l and 4 the thermally actuated pumpis shown in the compressor mode. In connection with the embodiment ofFIGURE 3, the compressor is shown in ,the self-actuated configuration asdescribed more fully hereinafter while in FIGURE 4 the compressor isshown in the by-pass mode as more fully described hereinafter anddescribed and claimed in Patent No. 3,285,001.

Thus, referring to FIGURES 1 and 2 there -is shown a thermally actuatedfluid moving apparatus in the compressor mode. The compressor comprisesin general a housing 30 defining a cylindrical chamber 31 within whichis positioned a oat valve 55 as described more fully hereinafter. In theembodiment shown a fluid inlet port 34 communicates with the chamber 31proximate the lower end wall 36 thereof. A gas outlet port 35 ispositioned through the top wall of the housing in communication with thegas portion 31b of the chamber. Suitable inlet 37 and 4outlet 38 checkvalves are positioned in the inlet and outlet ports to allow the flow offluid in the appropriate direction only. Suitable connectors 42 such asthreaded nipples are provided for connecting input 33 and output 32lines to the input and output ports. A heating element 45 is provided tosupply heat to the iiuid within the chamber as described hereinafter.Any conveniently available source of heat can be utilized, however, forpurposes of illustration an electrical resistance heater element isshown with a source of current 46.

From the upper portion of the chamber 3l a gas outlet port is providedthrough the top wall 49 of the housing and is operable from an open to aclosed condition by the oat valve 55. In the embodiment shown a gasoutlet port 50, designated hereinafter as the depressurizing port 50, islocated on the longitudinal laxis of the chamber and has a tapered seatS1 divergent from the port diameter to the chamber. A suitable connectorsuch as a threaded nipple 54 is affixed to the gas outlet port forconnection of a `depressurizing line 6l.

The float valve 55 is so formed and of suitable material as to bebuoyant in the liquid within the chamber 31. When the liquid is at afirst predetermined level which is suiiciently high within the chamber,the float valve is raised to a position at which it closes the gasoutlet port and retains it closed until the liquid level drops to apredetermined second level. Thus, in the embodiment illustrated thefloat valve 33 has a cylindrical body portion 56 with an upwardlyextending stem 57. The stem is vertically oriented in the orientation ofthe figures and is positioned on the -center point of the upper surfaceof the float valve body 56 such that it is substantially coincident withthe longitudinal centerline of the pump body. In its present embodimentthe oat valve is formed of nylon although other materials ycan beemployed as will become apparent in `connection with the description ofthe operation of the device and the function of the float valve. Thelength of the stem 57 is dependent upon the liquid level to bemaintained in the chamber and length of stroke of the liquid-gasinterface as described hereinafter. The stem has a valve element such asa metal ball affixed to its upper end and mateable With the valve seat51. The outside diameter of the float valve body 56 is substantiallyless than the inside diameter of the chamber 31 and is determined by thevolume of `liquid to be displaced to obtain the necessary buoyancyforces upon the iioat valve. The oat valve does not function in any wayto prevent passage of liquid or gas from one portion of the chamber tothe other. The function of the float valve is solely to open and closethe gas outlet port at a predetermined point in the cycle of the pumpdependent upon the combination of forces acting upon the float valve.The forces operating upon the float valve and its function can lmostreadily be seen in connection with the description of the operation ofthe invention in its most rudimentary form as shown in FIGURES l and 2.

Thus, referring now particularly to FIGURES 1 and 4 the compressor shownat a point in the cycle thereof where liquid is flowing into the pumpcompressor through the inlet check valve 37 which is open. The pressurewithin the compressor chamber 31 is at the pressure of thedepressurizing line 61 since the depressurizing port 50 is open. Thefloat valve 55 is at a position intermediate along its length of travelsince as shown in FIGURE l the liquid from the inlet has partiallyfilled the chamber. The iloat valve is freely oating within the liquidto a depth in the liquid determined by the buoyancy forces on the oatbody 56. Thus, the float valve body will be submerged in the liquid tothe depth indicated in the figures as a buoyancy line 73. As the liquidlevel con tinues to rise the iioat valve is carried upward until thevalve element 61 on the valve stem engages and seats Crt against thevalve seat in the depressurizing line. Upon closing of thedepressurizing line some immediate pres- Sure differential existsbetween the chamber and the depressurizing line and a sudden closing andseating of the valve is obtained. A force is caused by this pressuredifferential across the oat valve by reason of the fact that the uppertransverse surface of the float Valve against which the pressure withinthe chamber acts is less than the lower transverse surface by the amountof the area exposed to the depressurizing line as discussed more fullyhereinafter. After the float valve is seated the liquid level ceases torise within the chamber when the pressure of the fluid within thechamber slightly exceeds that of the fluid inlet line and causes theinlet check valve 37 to close. Since the heating element is energizedthroughout the operation of the pump, boiling of the uid occurs duringthe latter part of the iilling portion of the cycle. After the floatvalve closes the boiling of the liquid continues and produces vaporunder pressure in the chamber above the liquid level. This pressuredifferential between the chamber pressure and the depressurizing lineproduces a differential force in the upward direction to retain thefloat valve in its seated position. For purposes of discussion theportion of the chamber filled with liquid is designated as 3lb. Theliquid surface is an interface which moves upwardly and downwardlywithin the charnber comparably to the piston face in a mechanical pistonpump. As boiling occurs the pressure of the gas in portion Sib increasesas does the pressure of the liquid in portion 31a.

Referring now to FIGURE 2, the liquid level is shown at or near itsuppermost point immediately subsequent to opening of the outlet checkvalve 38. That is, after the inlet check valve and float valve haveclosed, boiling of the liquid continues and the pressure of the vaporand liquid in pressure balance continue to increase until the pressureof the liquid reaches and exceeds the pressure in the liquid outletline. At this point the outlet check valve opens. When the outlet checkvalve 38 opens, a new pressure balance is established. Since the volumeof gas generated by the boiling of liquid is substantially greater thanthe volume of liquid which is boiled to form such vapor the pressure ofthe vapor and the pressure of the liquid will remain constant at theoutlet pressure from the compressor; i.e., the gas pressure in theoutlet line. Consequently, gas will ow from the compressor through theoutlet line at a substantially constant pressure and the pressurebalance within the chamber 31 will remain substantially constant at thispressure as additional liquid is depleted and the liquid level movesdownwardly. So long as the volumetric rate of gas generated equals thevolume of gas passing from the compressor through the outlet line thepressure within the chamber will remain constant, gas will ow from theoutlet at such pressure, and the liquid level will move downwardly.Referring now to FIGURES 2 and 3, as the liquid level within the pumpchamber 31 decreases and passes below the upper surface 38 of the floatvalve body 56, the buoyancy force of the liquid acting upwardly upon thefloat valve begins to decrease. That is, the volume of liquid displacedby the float valve body 56 decreases as the liquid level passesdownwardly beyond the buoyancy line and a lesser volume of the iioatvalve body is submerged in liquid. It can be seen, however, that thepressure forces operating upon the float valve remain constant, in thatsince the vapor pressure and liquid pressure are equal, the pressureexerted upwardly upon valve body 56 by the liquid acting upon the lowersurface 65 of the valve body 56 is the same per unit area as the vaporpressure acting upon the upper surface S8 of the valve body. A pressuredifferential force thus exists since the upwardly directed forces due topressure upon the float valve exceed the downwardly directed pressureforces.

It should be noted at this point that although the weight of the floatvalve is referred to herein only as a gravity force and the device is ina vertical orientation, other force inducing means such as acceleration,centrifugal force or magnetic force can be utilized to obtain thenecessary force and pressure balances in accordance with the presentinvention when environmental conditions or other factors so require, asmore fully discussed hereinafter.

Thus, referring now to FIGURE 4 there is shown an alternative embodimentof the thermal compressor of the present invention in which a by-passconstruction is utilized. The fluid chamber, float valve, liquid inletline, and depressurizing line are identical in the illustrativeembodiment to those of the embodiment shown in FIG- URES 1 through 4 andare correspondingly identied. An outlet check valve 93 is positioned inthe port 90 and the gas outlet line 91 is the high pressure side of thecompressor at a pressure P1. A by-pass port 95 is in communication withthe pump chamber 31 at a position spaced downwardly a substantialdistance from the top wall of the chamber such that liquid or gas passesthrough the by-pass port dependent upon the liquid level within thechamber 31. The position of the by-pass port is predetermined todetermine the opening point of the depressurizing line as will becomemore apparent hereinafter. A restrictor means 97 such as an orifice oflesser diameter than the diameter of the by-pass port, or a throttlevalve, is positioned in the by-pass line to create a pressuredifferential under ow conditions between the chamber 31 and the by-passline 98.

In FIGURE 4 the by-pass embodiment of the thermal compressor inaccordance with this invention is shown in the condition where theliquid level within the chamber 31 has risen to a point at 'which thebuoyant float valve 55 has been raised into sealing engagement betweenthe valve stem element and the valve seat in the depressurizing port. Atthis point both the inlet check valve 37 and outlet check valve 93 arealso closed. By means of the energized heating element the temperatureof the liquid in the chamber 31 is raised to the point at which boilingcommences and the pressure of the gas in the gas portion 31h of thechamber and also that of the fluid in the liquid portion 31a of thechamber are raised. The rise in pressure first seats the float valvefirmly such that no leakage down the depressurizing line can occur.Secondly, a small quantity of liquid is by-passed from the compressor byflowing through the by-pass restrictor into the by-pass line and thenceto the low pressure side of the compressor. Since the quantity ofby-passed liquid is small due to the restriction in the line, theheating element continues to raise the pressure until the pressurewithin the compressor chamber 31 is equal to the pressure at the highpressure side of the compressor, i.e., at the gas outlet line 91, atwhich time the outlet check valve 93 opens and allows gas to be pumpedthrough the gas outlet line. The gas fiows through the outlet line atsubstantially constant pressure and at a rate at which the volume ofliquid owing during a given time interval is equal to the volume ofvaporized gas formed during that time interval. This process continuesuntil the liquid level lowers by depletion of the liquid to the point atwhich the liquid level is at the by-pass port. At the level of liquidwithin the chamber 31 at which it passes beneath the bypass port asudden pressure drop within the chamber occurs since the bypass port isnow in communication with the gas in the gas portion 31h of the chamber.Thus, gas rather than liquid is now forced by the high pressure throughthe bypass orifice and by the proper design of the orifice size thepressure drop across the restrictor drastically decreases the pressurewithin the chamber 31. As this pressure suddenly decreases the floatvalve drops and the depressurizing line is opened. Thus, as `describedhereinbefore just prior to the pressure drop due to the escape of gasthrough the by-pass line the pressure forces operating upon the floatvalve to maintain it in the closed position are a combination of thebuoyancy force of the liquid operating upon the oat valve body togetherwith the fluid pressure across the entire transverse lower surface ofthe valve body in the upper direction opposed by the weight of the oatvalve and the pressure of the chamber operating upon a lesser transversesurface area of the valve body. This pressure also maintains the outletcheck valve open and the inlet check valve closed. When the pressure isdecreased rapidly by the flow of gas through the by-pass line thepressure differential acting upon the upper and lower surfaces of thevalve body terminates as soon as the pressure within the chamber reachesthat within the depressurizing line. Thus, the Weight of the float valveheld in place by pressure forces causes it to fall, opening thedepressurizing line and completing the depressurizing of the pumpchamber to the low pressure point of the system. At this point theliquid head which feeds the inlet line to the pump chamber is suflicientto cause liquid to ll the pump chamber. As the liquid fills the chamberthe tioat valve is again buoyantly supported and elevated to theposition at which the depressurizing line is again closed and thepumping cycle is again initiated when the pressure within the chamberreaches the outlet line pressure. In this embodiment, when the liquidlevel is below the buoyancy line of the float valve at the by-pass levelthe float valve will drop and the chamber 31 will be depressurized. Theby-pass level can be made to occur at a point substantially beneath theoat valve. That is, the material of which the float valve is formed andthe configuration of the valve can be predetermined such that thedifferential pressure force upon the float valve is sufficient toovercome its weight and the float valve is maintained in the closedposition although no buoyancy forces are exerted upon it. Thus, in thecontext of the previous description the drop line is not within the bodyof the fioat valve and the oat valve will not fall to open thedepressurizing line until the pressure drop in the chamber due to thepassage of gas through the by-pass line is suffcient to reduce theupward differential force on the float valve below the weight of thefloat valve.

Referring now to FIGURE 5, there is shown schematically a refrigeratingapparatus in accordance with the present invention which utilizesconventional condensers, evaporators and expansion valves which aretherefore not shown or described in detail. In the embodiment of FIG-URE 5 a two component uid mixture is employed. In this embodiment onefluid component serves as a pumping fluid in the manner describedhereinafter to produce the pumping action while the second fluidcomponent provides the refrigerant action. The two fluids are designatedhereinafter as the pump Huid and the refrigerant fluid. No molecularinteraction between the two fluids can be allowed to exist. Freon 114 asthe pumping fluid and Freon 12 as the refrigerant fiuid are exemplary ofthe fluids which can be intermixed. Further illustrative combinations offluids are given hereinafter. yIn accordance with the present inventiona thermal compressor as shown in FIGURES 1, 2 and 3 is utilized as theprime mover for a refrigeration cycle which utilizes the standardcompression-condensation-expansion steps in the cycle. Accordingly, inFIGURE 5 there is shown schematically a refrigerant condenser andevaporator 101 with an expansion valve 102 positioned therebetween inthe fluid line 103 all in a manner well known to the art. The condenser100 is positioned exteriorly of the space to be cooled, i.e., at thehigh temperature side of the system while the evaporator is within thespace to be cooled, Le., at the low temperature side of the system. Asecond condenser 104 serves as a condenser for the pumping fluid and ispositioned at the low pressure side of the thermal compressor with inlet105 to the condenser 104 connected to the depressurizing line 61 of thethermal compressor and the outlet 106` from the condenser 104 connectedto the liquid inlet line 33 to the thermal compressor. Thus, the thermalcompressor cycles as previously described. During the liquid inletportion of the cycle a mixture of the refrigeration and the pumpingfluids are admitted to the chamber 31 of the thermal compressor. Afterthe float valve `has seated and closed the depressurizing line a supplyof gas is conducted from the thermal compressor through the gas outletline 91 to the refrigerant condenser 100. The high pressure gas expelledfrom the thermal compressor is admixed refrigeration fluid and pumpingfluid in the gaseous state. The two fluids are so chosen that in passingthrough the condenser 100 both the refrigeration fluid and pumping fluidare liquified while in passing through the expansion valve only therefrigeration fluid is again partially transformed to the gaseous state.Accordingly, through the evaporator 101 only the refrigeration fluidtakes on appreciable heat by vaporization. The intermixed pumping fluidin liquid state and refrigeration fluid in gaseous state are thenconducted to the fluid inlet of the compressor for the commencement ofanother cycle. The refrigerant fluid and pumping fluid released from thechamber 31 when the depressurizing line 61 is opened are conductedthrough the pump condenser 104 where the pumping fluid only is liquifiedafter which the admixed pumping liquid and refrigerant gas are alsoconducted to the compressor inlet line 33. In practice very littlerefrigerant fluid passes through the pump cycle as shown hereinafter.The steps in the above cycle can be clarified by reference to FIGURE 6in which the thermodynamic cycle is shown in separate pressure-enthalpydiagrams for the pumping fluid and refrigerant fluid. The pumping fluidcycle is shown as 6a while the refrigerant fluid cycle is shown as 6b.The intermixed fluids in gaseous form are pumped from the thermalcompressor 30 through a check valve 110 at high pressure and hightemperature. In the illustrative embodiment utilizing Freon 12 and Freon114 the outlet temperature of the intermixed gases from the thermalcompressor is 180 F. and the pressure is 140 p.s.i. which is theevaporation temperature and pressure of the pumping fluid Freon 114.Since the evaporating temperature of Freon l2 is 40 F. and theevaporating pressure is 50 p.s.i., the refrigerant fluid component ofthe intermixed gases leaving the thermal compressor is superheated.Thus, referring to FIGURES 5, 6a and 6b, the compressor outlet line 91is at the high pressure-high temperature point of the cycle at thepressure P as designated hereinbefore. -In FIGURES 6a and 6b the pointof the cycles of the two fluids at the outlet line 91 are shown as 91pon the pumping fluid diagram and 91r on the refrigerant fluid diagram.Thus it can be seen that at the outlet pressure of 140 p.s.i. andtemperature of 180 F. required for the vaporization of the F114 pumpingfluid, the pumping fluid is at the vapor stage 91p while the refrigerantfluid is a superheated vapor at 91r corresponding to the hightemperature Th of 180 at the high pressure P1 of 140 p.s.i. It can beseen that the pressure in the system of FIGURE 5 is at P1 through thecondenser designated the refrigerant condenser 100. The temperature ofthe condenser is near ambient and sufficient to reduce the intermixedgases to their condensing temperature which is 106 F. for therefrigerating fluid and 180 for the pumping fluid. Thus, as theintermixed fluids pass through the condenser 100 from line 91 to theinlet 103 to the expansion valve 102 they pass along the condensationline in FIGURES 6a and 6b from 91 to 103 and are reduced in temperaturefrom 180 F. to approximately 106 F. designated ambient temperature TA.It can be seen that at point 103 in FIGURE 6b the refrigerant fluid hasreached the condensation point of the pressure-enthalpy chart while thepumping fluid has been already liquified and subcooled from TH to TA,i.e., from 180 F. to 106 F. Thus, upon entering the expansion valve theintermixed fluids are both liquid and are at a pressure of 140 p.s.i.and a temperature of 106 which is the condensation pressure andtemperature of the Freon l2.

Across the expansion valve the pressure of the intermixed fluids isdropped to the low pressure of the systern P2. As shown in FIGURE 6b indropping from P1 to P2 the refrigerant fluid does so at constantenthalpy from point 103 to point 101a at the inlet to the evaporator101. At the inlet to the evaporator the fluids are therefore at apressure of 5() p.s.i. and a temperature of approximately 40 F. which isthe evaporation pressure and temperature of the Freon 12. As shown at101a in FIGURE 6b, the Freon 12 is partially liquid and partially gas atthis low temperature and in passing through the evaporator 101evaporates at the constant temperature of 40 F. and absorbs heat fromthe surrounding spaces. In passing through the evaporator the Freon 12which is part liquid-part gas at 101a as shown in FIGURE 6b vaporizesalong the constant pressure-constant temperature line from 10M to 101bat which point it is substantially all gas.

During the same period of the cycle the pumping fluid with which therefrigerant fluid is intermixed has been subcooled as a liquid from thetemperature at which it left lthe condenser to the refrigeranttemperature, i.e., from point 103 in FIGURE 6a to 101:1 at which it isat the temperature of 40 F. and pressure of 50 p.s.i. as describedabove. In passing through the evaporator from the point 101a to 101b ofthe thermodynamic cycle the pumping fluid does not change in pressure ortemperature since it is intermixed with the refrigerant fluid whichevaporates at constant pressure and temperature of 40 F. while thepumping fluid at this temperature is substantially below its evaporatingtemperature. Thus, points 101a and 101b are coincident in FIGURE 6a.Accordingly when the intermixed refrigerant and pumping fluids are inthe inlet line 33 to the thermal compressor the refrigerant fluid is anentrained gas in the pumping liquid and both are at a temperature yandpressure of 50 p.s.i. and 40 F. respectively. It can be seen that thepoint of the thermodynamic cycle at which the fluids leave theevaporator is dependent in part upon the temperature of the cooledspaces surrounding the evaporator and the heat transfer extent of theevaporator. Thus, the point 101b may occur in the evaporator or at thethermal compressor.

In the thermal compressor the temperature and pressure of the intermixedfluids are raised, as discussed hereinbefore, after sufficient liquidhas been admitted to the thermal compressor to seat the float valve. Thetemperature of the liquid within the thermal compressor is raised by aheat source until it is vaporized at a constant pressure of p.s.i. Thus,within the ther-mal compressor the refrigerant fluid is raised from thepoint indicated as 101b in FIGURE 6b to the point indicated as 91 whichis the outlet temperature and pressure of the refrigerant fluid from thethermal compressor. The refrigerant uid is thus raised from atemperature of 40 F. to 180 F. and from a pressure of 50 p.s.i. to 140p.s.i. As described hereinbefore the pumping fluid upon entering thethermal compressor is at the point indicated as 101b in FIGURE 6a whichcorresponds to point 101:1, the pumping fluid at this point being asubcooled liquid. Accordingly, in the thermal compressor the pumpingfluid in the liquid state is raised to the point at which it begins toevaporate at the lower pressure. That is, as shown in FIGURE 6a, as heatis supplied to the subcooled liquid its temperature rises along the linefrom 101b to 101b' at which the pressure has increased slightly and thetemperature has been raised to the point at which some evaporation atthe lower pressure commences. The temperature rise continues until thehigher pressure TH of 140 p.s.i. is reached at which time a constantpressure evaporation process is carried on in the thermal compressorfrom the point indicated as 91' to 91 in FIGURE 6a. Upon leaving thethermal compressor for the commencement of another cycle as describedabove the pumping fluid and refrigerant fluid are both in the gaseousstate at F. and 140 p.s.i.

Since the refrigerant fluid has a lower boiling pressure and temperaturethan does the pumping fluid the first gas pumped from the compressorwill be the refrigerant fluid and by the time the liquid level of theliquid within the thermal compressor has dropped to the point at whichthe float valve falls to open the depressurizing line. All of therefrigerant fluid has been expelled in compressed condition from thethermal compressor. Accordingly, through the depressurizing outlet thegas which is released from the thermal compressor to depressurize thecompressor and reduce the internal pressure thereof to the value of P2as described hereinbefore is substantially all pumping fluid. Thus, uponopening of the depressurizing port pumping fluid in the gaseous formescapes from the thermal compressor and is conducted through the pumpingfluid condenser 104 where it is reduced in temperature to theambientuReferring to FIGURE 6a the pumping fluid in the pumping fluidcondenser portion of the apparatus is throttled from the high pressureat point 91 of the pressure enthalpy diagram to the low pressure atpoint 105 after which it is condensed from point 105 to 106 through thepumping condenser. It then joins the intermixed pumping and refrigerantfluid in the inlet line 33 to the thermal compressor and enters thethermal cornpressor to commence another cycle.

Examples of other combinations of refrigerant fluids and pumping iluidsuch as Freon ll-Freon 2l with a PH=80 p.s.i.a., PL=49 p.s.i.a., TR=112F., Ta=144 F., TH=180 P. will be apparent :to those skilled in the artin view of the foregoing.

It Will be apparent from the foregoing that other em- =bodiments of thepresent invention can be employed in accordance with present invention.For example, liquid under pressure from the thermal compressor operatedin the pumping mode wherein liquid rather than gas is pumped therefromcan be utilized as the means for driving the refrigerant compressor.

Thus, the present invention provides an improved refrigeration methodIand apparatus.

What is claimed is:

1. Refrigerating apparatus comprising:

a thermal compressor having a housing defining a fluid chamber;

a fluid outlet from said chamber for conducting fluid under pressure;

a liquid inlet to said chamber;

a depressurizing outlet from said chamber coupled to a low pressureportion of said apparatus; means for vaporizing liquid coupled to saidchamber; liquid level sensing means for closing said depressurizingoutlet at a first liquid level and for retaining said depressurizingoutlet closed until sufficient of said liquid has been vaporized toreduce the volume of said liquid to a substantially lesser liquid level;

means in combination with said liquid inlet for opening said inlet atsaid second liquid level and closing said inlet at said first liquidlevel;

means in combination with said fluid outlet for closing said outlet atsaid second liquid level and opening said outlet at said first level;

said fluid being a refrigerant fluid;

a condenser;

means for conducting said refrigerant fluid through said condenser;

an expansion valve;

means for conducting said condensed refrigerant fluid through saidexpansion valve to partially ,vaporize said refrigerant fluid;

an evaporator;

means for conducting said partially vaporized fluid through saidevaporator for cooling the space surrounding said evaporator; and,

means for conducting said fluid to said thermal compresser.

2. Refrigerating apparatus comprising:

a housing defining a fluid chamber;

a vapor outlet from said chamber for conducting vapor under pressurefrom said chamber;

a liquid inlet to said chamber;

a depressurizing outlet from said chamber;

means for vaporizing said liquid within said chamber;

liquid level dependent means for closing said depressurizing outlet at afirst liquid level and for retaining said depressurizing outlet closeduntil sufficient of said liquid has been vaporized to reduce the volumeof said liquid to a substantially lesser liquid level;

means in combination with said liquid inlet for opening said inlet atsaid second liquid level and closing said inlet at said first liquidlevel;

means in combination with said liquid outlet for closing said outlet atsaid second liquid level and opening said outlet at said first level;

said liquid being intermixed pumping and refrigerant liquids whereinsaid refrigerant fluid has a lesser boiling point than said pumpingfluid;

a first condenser;

means for conducting said vaporized fluid under pressure through saidcondenser;

an evaporator;

an expansion valve interposed between said condenser and saidevaporator;

means for conducting said fluid through said expansion valve and saidevaporator for cooling the space surrounding said evaporator;

means for conducting said fluid from said evaporator to the liquid inletof said thermal compressor;

a second condenser;

means for conducting vapor from said depressurizing outlet through saidcondenser to said liquid inlet of said thermal compressor.

3. A device for moving lluid under pressure comprising:

a housing defining a fluid chamber;

heating means for vaporizing liquid within said chamber;

a liquid inlet to said chamber;

a vapor outlet from said chamber for conducting vapor under pressurefrom said chamber;

a depressurizing vapor outlet from said chamber;

a float valve movable between a first yancl a second position Withinsaid chamber, said float valve being buoyantly movable from said secondposition to said first position by liquid within said chamber as saidliquid rises to a first predetermined level;

means in combination with said lloat valve for closing saiddepressurizing outlet at said rst position thereof, said depressurizingoutlet being open at said second position;

means in combination with said float valve for retaining said floatvalve at said first position until said liquid falls to a predeterminedsecond level substantially below said first level;

means in combination with said liquid inlet for opening said inlet atsaid second liquid level and closing said inlet at said first liquidlevel;

lmeans in combination with said liquid outlet for closing said outlet atsaid second liquid level and opening said outlet at said first level;

said liquid being intermixed pumping and refrigerant liquids whereinsaid refrigerant fluid has a lesser boiling point than said pumpingfluid;

a first condenser;

means for conducting said vaporized fluid under pressure through saidcondenser;

an evaporator;

an expansion valve interposed between said condenser and saidevaporator;

means for conducting said fluid through said expansion valve and saidevaporator for cooling the space surrounding said evaporator;

means for conducting said iluid from said evaporator to the liquid inletof said thermal compressor;

a second condenser;

means for conducting vapor from said depressurizing outlet through saidcondenser to said liquid inlet of said thermal compressor.

4. A device for moving uid under pressure cornprising:

a housing defining a closed uid chamber;

a liquid inlet to said chamber;

a vapor outlet from said chamber for conducting vapor under pressurefrom said chamber;

a depressurizing vapor outlet port from said chamber;

heating means for vaporizing liquid within said chamber whereby saidchamber contains a volume of liquid and a volume of vapor, said heatingmeans being adapted to supply heat suicient to vaporize said liquid andraise the pressure of said fluids within said chamber to a high pressureP1 from a lower pressure P2;

a oat valve adapted to be buoyantly supported by said liquid and movedto a rst position by increase of the liquid volume in said chamber to arst predetermined liquid level;

said float valve being so constructed and arranged as to provide a valveelement portion adapted to seat in and close said depressurizing port insaid iirst position of said float valve, the pressure at the exterior ofsaid port to which said valve element portion is exposed being at apressure P3 less than P2 such that in said first position said floatvalve is urged toward said irst position by the buoyancy force of saidliquid and the force exerted by the pressure diierential between P1 andP3 acting upon said oat valve, said float valve being urged away fromsaid rst position by the weight thereof whereby said oat valve is movedto a second predetermined position by decrease of the liquid volume to asecond level at which the buoyancy force and diierential force are lessthan the weight force of said oat valve, said depressurizing port beingopened by movement of said oat valve from said first to said secondposition;

outlet check valve means adapted to open said iluid outlet when saidfluid pressure within said chamber reaches the higher pressure P1 andclose said fluid Outlet when said pressure is less than P1;

inlet check valve means adapted to open said liquid inlet when saidchamber pressure is less than P2 and close said liquid inlet when saidchamber pressure exceeds P2;

said liquid being intermixed pumping and refrigerant liquids whereinsaid refrigerant Ifluid has a lesser boiling point than said pumpinguid;

a first condenser;

means for conducting said vaporized fluid under pressure through saidcondenser;

an evaporator;

an expansion valve interposed between said condenser and saidevaporator;

means for conducting said Huid through said expansion valve and saidevaporator for cooling the space surrounding said evaporator;

means for conducting said fluid from said evaporator to the liquid inletof said thermal compressor;

a second condenser;

means for conducting vapor from said depressurizing outlet through saidcondenser to said liquid inlet of said thermal compressor.

References Cited UNITED STATES PATENTS MEYER PERLIN, Prima/y Examiner.

